1. Field
The present disclosure relates to a filter.
2. Description of Related Art
In accordance with the rapid development of mobile communications devices, chemical and biological devices, demand for small and light, filters, oscillators, resonant elements, acoustic resonant mass sensors, and the like, used in such devices, has also increased.
A film bulk acoustic resonator (FBAR) has been used as an element for implementing such small and light, filters, oscillators, resonant elements, acoustic resonant mass sensors. Such FBAR may be mass-produced at a minimal cost to have subminiature size. In addition, the FBAR may have a high quality factor (Q) value, a main characteristic of a filter. The FBAR may be used in a microwave frequency band that allows for use of particular bands of personal communications systems (PCS) and digital cordless systems (DCS).
Recently, as wireless terminals have been implemented with the ability to support communications within a plurality of bands, a plurality of filters controlling the plurality of bands have been used in the wireless terminals. However, when the number of filters controlling the plurality of bands increases in correspondence with the an increase in the number of bands, signal processing processes become complicated, while manufacturing costs and the size of the filters module may increase.